The present invention relates to a novel steering device suited for use in boats, and more particularly to a steering device constructed so as to be lightly operated regardless of the rotation direction of a steering wheel.
A conventional steering device of this type is provided, for instance, as shown in FIG. 1, with a disc drive member 26 rotatably mounted in a casing 25 and an expansion and contraction-durable, flexible inner wire 27, one end 27a of which is fastened to an outer peripheral surface of the drive member 26, and is so constructed as to actuate a rudder means connected to the other end of the inner wire 27 by turning a steering wheel (not shown) to rotate a pinion 28 whereby a drive member 26 having a gear 29 meshed with the pinion 28 is rotated to wind or unwind the inner wire 27 into or out of the casing. When the drive member 26 rotates to wind the inner wire 27, the inner wire 27 contacts closely with the periphery of the drive member 26 and scarcely contacts slidingly with the inner surface of the casing 25, since the pull load acts on the inner wire 27. However, when the drive member 26 is rotated in the reverse direction to unwind the inner wire 27, the inner wire 27 separates from the periphery of the drive member 26 and contacts with the inner surface of the casing 25 to cause frictional drag and, accordingly, the steering device of this type has the disadvantage that the turning of the steering wheel becomes heavy and a boat is steered with difficulty.
In order to eliminate this disadvantage, it is also proposed to locate bearings between the inner surface of the casing and the inner wire, each of the bearings being rotatably mounted on a large number of pins fixed to the casing, or as shown in FIG. 1, to secure a lubricating member 30 of plastic material having an excellent lubricating property to the inner surface of the casing 25. However, the former has the defect that the frictional resistance is not sufficiently decreased, despite of requiring much labor in the preparation of the steering device. Also, the latter has the defect that the gap between the drive member 26 and the lubricating member 30 becomes large during use for a short period of time due to abrasion of the lubricating member 30, so the inner wire 27 causes backlash, and as a result, a rudder swings on sail in spite of no rotation of the wheel and a boat moves in a zigzag direction.
Like this, there has not been known a steering device which can sufficiently eliminate the defect of change in light and heavy of steering depending on the rotation directions of the steering wheel with simple construction and with low cost.